These are the slides to accompany the second lecture from Lesson 5 of Maps and the Geospatial Revolution on Coursera. www.coursera.org/course/maps/

1. Maps and the Geospatial Revolution
Lesson 5 – Lecture 2
Anthony C. Robinson, Ph.D
Lead Faculty for Online Geospatial Education
JohnA. Dutton e-Education Institute
Assistant Director, GeoVISTA Center
Department of Geography
The Pennsylvania State University
This content is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License

2. Choosing Colors
• Colors on thematic maps should correspond to
the type of data you’re trying to show
– Do you have numerical or categorical data?
• Color schemes include three major types
– Sequential (less -> more)
– Diverging (above and below an average)
– Qualitative (pizza, currywurst, and tonkatsu)

3. Sequential Colors

4. Sequential Colors

5. Diverging Colors

6. Qualitative Colors

7. Rainbows Kill People
• Rainbow (spectral) color schemes are commonly misused on
maps
– Weather maps showing precipitation amounts
– Every “heat map” floating around
• They’re bad because they often use qualitative colors to show
sequential or diverging data
– Is blue more than yellow? Is purple more than blue?
• They also can kill people
– Doctors interpreting medical images of the heart made worse
decisions about their patients using rainbow schemes than simple
sequential schemes

8. Rainbows Kill People

9. Rainbows Kill People

10. Data Classification
• Assigning observations
to categories is called
data classification
• Three major types to
know
– Equal Interval
– Quantile
– Natural Breaks

11. Equal Interval Classification

12. Quantile Classification

13. Natural Break Classification

14. Text On Maps
• Designing text on
maps is a major
aspect of
cartography
• Choosing fonts and
positioning labels can
be a daunting task
– Labeling every
street, building,
etc… and making
them all readable
together

15. Maps and the Geospatial Revolution www.coursera.org/course/maps
Twitter @MapRevolution
Online Geospatial Education @ Penn State www.pennstategis.com
This content is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License